Ball-bearing caster.



T. L. GARDNER.

' BALL BEARING CASTERE anomdoz ZJ- Gard/zen UNITED s THOMAS L. GARDNER, OF AKRON, OHIO.

BALL-BEARING CASTER. I

Specification of Letters Patent.

Patented Sept. 19, 1916.

Application filed October 28, 1915. Serial No. 58,464.

To all whom it may concern I I Be it known that I, THOMAS L. GARDNER, a citizen of the United States, residing at Akron, in the county of Summit and State body of the caster and removed therefrom when required.

Another object of the invention is to provide a device'of this character embracing a plurality of relatively small anti-friction balls which are held in position within the body or supporting portion of the caster and will not fall therefrom whenthe larger bearing ball is detached, while at the same time the smaller balls may be readily de tached by applying a suitable implement thereto.

With these and other objects in view the invention consists in certain novel features of construction as hereafter shown and described and then specifically pointed out in the claim.

Referring to the drawings, Figure 1 is a side elevation of the improved device; Fig. 2 is a bottom plan view of the parts shown in Fig. 1; Fig. 3 is an elevation with the lower portion in section on the line 3-3 of Fig. 1'; Fig. 4 is a transverse section on the line 4.4 of Fig. 3. Corresponding and like parts are referred to in the following description and indicated in allv the views of the drawings by the same reference characters.

The improved device comprises a body or stock 10 having means such as a spindle 11 of the usual construction whereby the stock may be supported from a table leg, bedstead, or other article of furniture. The body portion 10 is preferably flared outwardly and downwardly and is formed with a fiat lower face 12 and is reduced at the edge to form an externally threaded annular shoulder 13. Formed in the lower face of the body 10 is a cavity, represented as a whole at 14, and with an annular runway or channel 15 somewhat larger than the intake end of the cavity andlikewise extending above the bottom of the cavity whereby a downwardly projecting central portion 16 having a con vex face is produced. The annular runway 15 is designed to receive a plurality of antifriction balls 17, the balls being limited in their inward movement and supported in posltion by the downwardly projecting central portion 16 ofthe stock. Bythis arrangement it will be obvious that when a suflicient number of the balls 17to completely fill the runway 15 are disposed Within the cavity, as shown in Fig. 4, with their adjacent faces in contact, the depressed central portion 16 will operate to retain the balls in place and prevent them from dropping downwardly, while at the same time the balls may be readily removed by exerting a slight downward pulling movement thereon. It will be understood,

however, that said balls -can not-be removed except force be applied to detach them. A relatively large bearing ,ball 18 is disposed within the cavity 14 and in contact with the smaller anti-friction balls 17 as illustrated in Fig. 3. A holding member 19 having a central cavity 20 forms a part of the improved device, and is provided with a threaded rim 21 to engage the threads 13 of the stock 10 and-with a flat upper face 22 to engage against the flat lower face 12 of the stock, as shown in Fig. 3. The socket or cavity- 20 .of the member 19 underlaps the runway 15 may be turned on a suitable machine, and all the other portions turned true, at small expense, so that the improved device runs true and smooth. A suitable oil duct 23 is formed in the head 10, as

shown in Fig. 3, to enable the balls to be lubricated, if required.

Having thus described the invention,

what is claimed as new is A caster including a head having a socket formed therein and provided with a projection depending from the head immediately above the socket and having a convex lower face surrounded by an'annular runa plurality of anti-friction balls seated in Way, portions of the walls of the runway the runway and bearing against the master being formed by the convex face of the proball, and a retaining cap holding the master jection and other portions thereof being inball in contact with the anti-friction balls 5 clined downwardly and intersecting the and serving to prevent accidental displace 1-5 Walls of the socket, there being an oil duct ment of said anti-friction balls when the formed in the upper portion of the head parts are assembled. and communicating with the annular run- Intestimony Where0f,I afiix my signature. way near the convex lower face of the pro- 10 jection, a master ball seated in the socket, THOMAS L. GARDNER. [L.s.] 

